Today is the 30th anniversary of the explosion of the Space Shuttle Challenger. I can see form twitter that a lot of folks who are roughly my age have a similar memory of being brought out of class to watch the launch, thanks to the presence of astronaut and teacher Sally Ride. I remember it being sad and being affected by it, but as a child, things outside of your life are necessarily more abstract. Of course, when the Space Shuttle Columbia broke up over Texas in 2003, I also remember it as sad, but not impacting my life in as major a way. I don't have any vivid memories of where I was when that disaster happened. It's strange that something can be both formative and abstract when you're young, but a similar disaster feels both more concrete and more diffuse.

The long term implication of both disasters, of course, was the curtailment of manned space exploration. While there is an undeniable romance to manned space flight, it just doesn't make much sense. Space is dangerous, and inhospitable. The Apollo 13 disaster aside, it's vanishingly unlikely that a scenario like The Martian would play out that way in real life. Compared to the incredible advances over the last twenty years of robotic and unmanned probes -- the Martian Pathfinder, Spirit, Opportunity and Curiosity, the New Horizons probe opening up a view of Pluto to us for the first time, the ESA Rosetta and Philae comet probes -- have returned an amount of science and wonder that I do not believe that manned space exploration could surpass -- if not equal.

Science will continue, and more wonders will be discovered. The crews of the Space Shuttles Challenger and Columbia died in the pursuit of knowledge, and I remember them.